Making the CO2 footprint of food choices salient, makes people chose the better alternative
What unsustainable behavior needs to change: In 2013 when the Green Party in Germany demanded a veggie/vegan day in company, school or university canteens, the outcry was massive: “Cancel culture.” “Don’t take away our freedom!” “Political paternalism!”. The idea was not only to create awareness for a diet with less meat but to directly reduce emissions.
However we need to recognize that meat consumption is a big driver for CO2 emissions that expedites global warming. Western Europeans eat 10x more meat than people living in India. Eating meat has societal as well as personal consequences: A fat-heavy diet often leads to obesity and severe health issues like heart attacks.
The problem: most often the negative externalities of meat consumption are hidden. Most people don’t know how much CO2 emission their steak is responsible for how a meat dish compares to a veggie option.
So the question is: how can we become choice architects that just nudges a decision instead of telling people what to do.
The Green Nudge: In a joint effort the Ludwig-Maximilians-Universität München, Humboldt-Universität zu Berlin and the Aalto University wanted to examine if making negative environmental impacts like CO2 emissions more salient, would nudge people to adapt their choices.
In a 10 day field experiment in one of the biggest university canteens in Munich with over 8.000 visitors (during that 10 day time period), the researchers introduced menu displays showing the food option but also the environmental externalities like the CO2 footprint
The interesting bit: their experimental design included testing different options of how to visualize the negative footprint.
Variables were:
➡ the negative cost in €
➡ the amount of an individual’s daily CO2 budget spent
➡ the amount of CO2 emissions
They introduced traffic light colors: green for dishes with low CO2 emissions, yellow for more emissions and red for the “climate-killer-lunch”.
The result: the demand decreased for CO2-intensive choices with meat and fish and thus reduced the footprint of the total lunch menu. The researchers could observe the biggest effect when visitors learned how much environmental cost (in €) their lunch would cause. So making something intangible more salient resulted in almost 10% less CO2 emissions compared to days when they didn’t show any negative environmental impact on the menu displays.
Providing feedback with a smart packaging solution by Mimica
What unsustainable behavior needs to change:
According to the Waste Resources Action Programme (WRAP) we waste a staggering amount of 88 million tons of food every year because of the expiration date. So, we are wasting food only because a print on the product says it has reached its end of shelf life- even if it was still good to consume.
The thing is: it’s often hard to say if food has gone bad or not. Of course there is the good old: “Look, smell, taste” but obviously this proves difficult for packaged food. It is hard to tell if food is safe to eat beyond the expiration date, unless you see some nasty mold on it. The process of decay is extremely abstract and people – when in doubt – prefer to play it safe and throw it away. This is not only valid for people in front of their fridge. For retailers, it has a significant cost effect. When a product nears it’s expiration date, it often will go on discount or is thrown out.
So one tool to reduce food waste would be something that makes the abstract more concrete. Some mechanism that extends the product and shelf life. If only the food or packaging could talk and stop this unsustainable behaviour.
The Green Nudge:
To address this challenge, salient feedback can be a great nudge to trigger action. Feedback coming from the product. More precisely: from the packaging.
London-based start-up Mimica came up with a game-changing, bio-inspired packaging innovation. Their Bump products are temperature-sensitive, dynamic expiry labels for food or beverages. The labels – coming a tag or cap – contain a gel filling that goes from smooth to bumpy at the same pace as the food inside deteriorates. This way they provides accurate, real-time feedback of the product’s freshness with a tactile interface.
Mimica founder Solveiga Pakštaitė was inspired by the banana skin transformation which changes its colour and texture as it ripens. One of nature’s great ways to provide feedback: green = don’t eat, yellow = eat, turning brown = hurry, it will go bad soon.
Opower’s neighbour comparisons. Saving energy by making sustainable peer action salient.
What unsustainable behavior needs to change:
Let’s go back a couple of thousand years in time. One of our hairy ancestors observes another gatherer picking some fruits from a bush and eating them. Some time later the fruit picker is still alive and well. This day she learned that eating those fruits won’t kill her or her family.
Evolutionary psychology suggests there are five ancestral forces that have shaped human perception and behaviour. In this case: Social imitation.
It refers to the important lesson that human beings learned a very long time ago and which secured our survival: imitating others is the most efficient way to learn. Our brain is therefore wired to do what the majority does.
Unfortunately, the majority of people often influence each other into adverse habits – especially when it comes to the environment. Social scientists have demonstrated the influence of peer behavior in a host of areas. We’ve been building bigger houses, driving heavier vehicles, flying to remote destinations or engaging in a host of other energy-intensive activities. A dominant reason we are doing these things is our tendency to behave as our peers do.
The Green Nudge:
There’s reason to believe that peer effects could be similarly beneficial to our climate future.
Utility Companies, for example, have found that customers reduce their electricity usage significantly when told how their consumption compares with that of neighbors.
Opower, a home-energy-management company owned by Oracle, has helped deliver these customer-comparison reports to millions of households served by utilities around the globe; it boasts that the program has helped save enough energy to power San Francisco’s homes for more than 10 years.
Google, the manufacturer of smart Nest thermostats, has incorporated the approach into its product: It rewards customers who choose energy-efficient settings with green leaf icons in their monthly usage summaries, and compares the number of leaves earned with those of other Nest users in the area.”
From Robert H. Frank’s book, Under the Influence: Putting Peer Pressure to Work.
Copenhagen’s elevated benches make future consequences tangible
What unsustainable behavior needs to change: In an episode of The Simpsons, when Homer is confronted with his responsibilities, he decides to avoid them with the words: “That’s a problem for Future Homer. Man, I don’t envy that guy.” Only to then pour vodka into a jar of mayonnaise and drink it.
What might seem to be the typical behavior of Homer, is not untypical behavior of human beings. We act as if we only live in the present. We smoke, although we are aware it might cause lung cancer. We eat that whole chocolate bar, although we know that it will make us fat and unhealthy. We drive that SUV, although we know (well at least the majority of us) that it will drive excessive amounts of CO2 emissions into the atmosphere. Yet, we still do it.
This effect is called Hyperbolic Discounting. The perception that the present is more important than the future, impedes our ability to take action on problems that feel distant and slower. Thus we tend to choose a smaller but sooner (now) reward over a larger but later reward. Like your everyday processed meat cravings, that may damage your heart’s health in the long-run. We discount the value of a healthy Future Me in favor of a happy young Today Me.
Same goes for our Future Climate. It is something far away, very abstract. Additionally Climate change is slow moving, you don’t immediately see your impact when you change a behavior like stopping eating meat. All that makes us like: Why should I care about it?
This short-term “thinking” is a relic of our old days as human beings. It’s from a time when evolution told us to replicate, to have as many offspring as possible, but not necessarily to stay healthy or keep our world a great place to live in.
The Green Nudge: Sitting on one of the elevated benches might not have an immediate effect on your behavior. But the benches make future consequences visible. It makes the Future Me meet the Today Me. For some it could have an effect that affects their behaviour: they might use public transportation more often, instead of their car; they throw away less food; they eat a little less meat or they don’t take short-distance flights, but the train.
A new default with Burger King’s “normal or with meat” campaign
What unsustainable behavior needs to change:
Eating meat is deeply ingrained in Western culture, often seen as the default choice for protein and nutrition. But this comes at a high environmental cost. According to the Food and Agriculture Organization (FAO), global livestock production contributes 14.5% of all human-caused greenhouse gas emissions—equivalent to 7.1 gigatons of CO₂ per year.
Beef, in particular, is a major emitter. Producing just 1 kg of beef releases around 60 kg of CO₂ equivalents.
By comparison, the emissions per kg for other foods are significantly lower:
- Root vegetables & apples: 0.4 kg CO₂
- Peas: 1 kg CO₂
- Rice: 4 kg CO₂
- Tomatoes: 1.4 kg CO₂
- Nuts: 0.3 kg CO₂
- Bananas: 0.7 kg CO₂
Despite these environmental impacts, meat remains the default in many popular dishes—especially burgers. When customers order a burger, it’s almost always assumed to be meat-based. This default reinforces unsustainable choices.
The Green Nudge:
Burger King Austria set out to challenge this norm with its „Normal or With Meat“ campaign at its Vienna Margaretengürtel location. Instead of assuming meat, they flipped the default: customers who ordered a “burger” without specifying “with meat” received a plant-based version by default.
The results: a 40% increase in plant-based burger sales revenue. While further research is needed to assess long-term behaviour changes, this experiment suggests that default nudges can have a powerful impact on food choices.
Changing habits is extremely difficult. But establishing a new default might nudge some people to reconsider and try new – ideally more sustainable – options. If the product experience is not worse than the unsustainable option, it has the chance to become a new habit. A new normal.